Deadbolt Installation in Thornbury, Delaware County, PA

A front door with only a knob lock has one locking point, with no separate lock securing the door to the frame.

In Thornbury, we install deadbolts on entry doors when you want that additional lock. The bolt needs room to extend fully into the frame, rather than stopping short against the strike. We set the strike so the bolt moves into its opening cleanly when the door is closed. That alignment matters because a lock that turns only partway may not be securely engaged.

For a door with glass nearby, a double cylinder puts a keyed lock on the inside as well as the outside. The interior key prevents the lock from being turned through broken glass, but you need that key to open the door from inside. A single cylinder has an interior thumb turn, so you can leave without finding a key, although the turn is reachable through nearby glass. If you want the new lock to use the same key as your other locks in Thornbury, we can check whether they are compatible and explain your options.

We look at the door material and thickness, the space around the existing knob, and how the door meets the frame.

A glass panel close to the lock affects your choice: someone reaching through broken glass might be able to turn an interior control. Before starting, we explain the available options and their tradeoffs, including whether a compatible model could use your existing house keys.

A single cylinder deadbolt takes a key outside and has a turn piece inside. A double cylinder needs a key on both sides, which limits access through nearby glass but also means you need that key to leave. Once you choose, we install the hardware and set the strike in the frame. We check that the bolt extends fully when the door is closed, rather than stopping short or rubbing against the opening. We then show you how it operates so you can try it from both sides and see that it turns cleanly.

Your front door now has a deadbolt as well as the knob lock.

Use both when you secure the door, and check that the new deadbolt engages without pulling, lifting or pressing hard on the door. If turning it feels easy with the door ajar but difficult with it closed, the strike may be out of alignment. Do not force it or keep using it if it catches partway, since that can make the problem worse.

Keep the keyway clear of dirt, and use a lubricant made for door hardware sparingly if the mechanism begins to feel sticky. Avoid household oil, which can collect grime. If yours takes a key on both sides, keep one in a consistent, easy to reach place for leaving. If binding continues, the bolt will not engage fully, or a key starts to bend, call us to check it.